Note 6 - Fair Value - Summary of Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2021		Dec. 31, 2020
Cash and cash equivalents	$ 18,129	[1]	$ 16,363
Restricted cash	1,154		1,166
Short-term investments	80,262		0
Long-term investments	37,435		0
Total assets measured at fair value	136,980		17,529
Contingent consideration	2,371		3,936
Total liabilities measured at fair value	2,371		4,191
Warrant liabilities	0		255
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	18,129	[1]	16,363
Restricted cash	1,154		1,166
Short-term investments	0
Long-term investments	0
Total assets measured at fair value	19,283		17,529
Contingent consideration	0		0
Total liabilities measured at fair value	0		0
Warrant liabilities			0
Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	0	[1]	0
Restricted cash	0		0
Short-term investments	80,262
Long-term investments	37,435
Total assets measured at fair value	117,697		0
Contingent consideration	0		0
Total liabilities measured at fair value	0		0
Warrant liabilities			0
Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	[1]	0
Restricted cash	0		0
Short-term investments	0
Long-term investments	0
Total assets measured at fair value	0		0
Contingent consideration	2,371		3,936
Total liabilities measured at fair value	$ 2,371		4,191
Warrant liabilities			$ 255

[1] Includes investments that are readily convertible to cash with original maturities of 90 days or less.